Advice on engine sought....hone or full rebuild?

[robertverhey]

As you may have gathered from my rebuild thread, I recently restarted the engine of my S3. According to the paperwork I received with the car, it appears that a rebuild was carried out in 1983, and then the car basically "sat" for nearly 30 years.

Compressions are good, around 170-180 pounds. The engine runs quietly and smoothly. I think the head has been well refurbished. But the engine is smoky. Smoky on idle, and emits quite a cloud on a throttle blip. Definitely oil smoke. Too much to pass a roadworthy inspection.

I was once advised by the legendary Bob Holden that the best way to cure a smoky motor following a rebuild is to take it for a damn good thrashing up the Bells Line of Road (sydney locals will know what he meant), to properly bed the rings in. But of course that option is not available until the car is registered....which won't be happening while it's smokin'....catch 22

Given the otherwise healthy state of the engine, and the somewhat unhealthy state of my budget, I'm planning to do an in-situ flexi-hone of the engine, after removing the head and sump and rods/pistons (spyder chassis with removable crossmember).

Just tapping the collective wisdom out there, is this a feasible, practical way forward? Or would I be better to bite the bullet and pull the engine out? I have a hoist, so access from underneath is easy. But is it a challenge to get the sump mounted and sealed properly in situ? Would I be wise to replace the oil control rings at same time? Or is honing likely to do the trick, using the existing rings?

I could potentially get out of this quite cheaply (ie cost of a sump gasket and head gasket) if I'm successful.

Any advice would be welcomed.

Robert

[bill308]

Robert,

You might consider putting the car on a chassis dyno (rolling road) for a 1 hour session and run it under various controlled loads. See what happens.

Bill

[alan]

imho remove engine, lift off head, drop sump.
If the engine was not turned over during the 30years rings can make rust lines in bores.
I think you need to remove pistons, deglaze bores and fit new rings.
Also because the engine stood for a long time there will be thick sludge to remove in the sump

[rgh0]

Hi Robert

Was the engine used after the rebuild in 1983 or just built and never run?

If not run then the rings may need bedding but as you have good compression I sounds like the rings are reasonably bedded in already? The smoking you describe could be from the valve guides and stem clearance not being correct also. I presume your exhaust is new and does not have old oil sitting in it

Two choices I think

1. Find a rolling road as suggested and run it under load for an hour to see if this helps bed in the rings and stop the smoking. If it does not stop then your down to step 2.

2. Pull the head and check the guide to valve stem clearance. If that's Ok then have a look at what the bores look like and hone if they need it. I would fit new rings if you hone it. Once you have the head off its probably easier to remove the engine block and do the honing on a bench or send out for a professional hone job if its needed. You could do it in situ but refitting the sump so it does not leak is not all that easy

cheers
Rohan

[robertverhey]

Thanks for all that advice, albeit not what I was hoping not to hear! Love the rolling road idea, but alas no ready access to one.....but might do a bit of local googling....

The exhaust is a new one, the oil was really clean on arrival (as was the coolant), but both have been replaced. No sign of sludge in what came out, but who knows what awaits in the base of sump.

I only have it verbally but I don't think the engine was run much if at all after rebuild. One of those long term, stalled resto projects. Pages and pages of valve adjustment info provided leads me to believe that the head was pretty well dealt with, and it runs sweet as.....anyway won't know till the head's off.

I will pull the head off in situ, have a good look down the bores and then take it from there....all things considered, probably an engine out job.

[Type28]

I wouldn't start taking it to bits until it had a decent run. I recall thinking my engine was knackered when I first run it in my car after a professional rebuild. The smoke screen behind me was like something out of a batman film. The smoke cleared after a very embarrassing mile or two.

[robertverhey]

Hmm food for thought......any good dyno recommendations in Sydney? People who know what an elan is and are likely to want to assist for a reasonable price? I can trailer the car so any suburb is okay......

[rgh0]

Talk to Maurice Blackwood or Keith Edwards from CLA they should know a decent Elan friendly dyno place, or know someone who will know

cheers
Rohan

[Panda]

Hi Robert,
Keith is in hospital so can't help at the moment. As always, Rohan's advice is spot on. I know two chassis dynos in Sydney. I have used Superior Auto Sport,79 Bassett St. Mona Vale. 9979 6289. I have also dealt with Tilley Racing in Brookvale. 9905 0105. Very helpful and friendly, but I haven't used their dyno.
Well worth a try. Don't pull engine apart in the car, head off is ok, but not sump. Too hard and difficult to seal properly. It's only an extra hour once the head is off to take the engine out.
cheers
Alan Pate

[robertverhey]

Thanks for that Alan, some useful contacts I'll follow up. And thanks to others too for advice. the consensus seems to be not to faff around with an in-car hone, and do it properly on an engine stand. So be it. Another option has occurred to me today, I'm also restoring a Mk2 lotus cortina, which has a good smoke free Owen wuillemin long stroker (one of his very last, a very treasured motor). As the Corty is likely to get registered first, once it's running I could "borrow" the ?lan motor one weekend and go for a brisk run..